Every few months, it seems, we hear a new version of an old story: the maker of an expensive smartphone announces it won’t be upgraded to the latest version of Android, and consumers cry foul.

But this one is different. First, Motorola told customers they would upgrade the phones for 18 months after they came out, a statement that drove sales of the devices. Second, Google owns both Android and Motorola, making it all the more puzzling why the business units didn’t work together to make an upgrade happen.

Finally, there are signs that for some Android devotees, Motorola’s abandonment of its year-old phones is the last straw.

To me, the interesting part of this isn’t Motorola breaking its promise — although I’d be plenty steamed if I’d bought a phone based on it — but the obvious technical difficulty of updating a phone that uses one version of Android to a new version. If it were easy, we wouldn’t have the fragmentation mess.

I understand that getting an operating system to run on hundreds of phones from a bevy of manufacturers is far tougher than making it run only on hardware you build yourself. That’s why iPhone buyers know they’ll get updates the moment a new version of iOS is ready, while Android buyers don’t know what to expect. But as I keep saying, I don’t think that Google and phone makers have the option of ignoring the problem. The longer it festers, the more often it’ll come back to bite them, and their customers.

I mean, it can’t be good for Motorola to tick off customers so badly that they go out of their way to avoid its products in the future, can it?